Vanderbilt received a Governor’s Environmental Stewardship Award for The Commons as one of 14 award winners recognized statewide for their positive impact on the state’s natural resources.
Black + Gold = Green
When it comes to sustainability, Vanderbilt is rewriting the equation. Read the full story in the Vanderbilt View.
Electronics Recycling Event a Huge Success
The Vanderbilt-sponsored Electronics Recycling Event filled 25 tractor trailers with electronics for recycling, with more than 1,000 people dropping off items during the community recycling event.
Vanderbilt Takes First Steps at "Greening" Commencement
Vanderbilt evaluated Commencement and related activities to see where "greener" practices could be adopted.
The Discovery Channel's Mythbusters Test the Effects of Turning off the Lights
THIS MYTH IS FEATURED IN: Original air date: 12/13/2006 |
In an episode of the Discovery Channel's hit popular science show, Mythbusters, the cast tests if turning the lights off every time you leave the room really conserves energy. Details about the experiment and its results are included below...
Myth Title: Lights On or Off?
Myth Description: Do you really save money turning off the lights when leaving the room even for a brief moment? And, does turning on and off the lights often reduce the longevity of the bulbs?
MythBusters on the bust: Kari, Tory, and Grant
Hypothesis: The "start up" burst of energy consumes more energy than leaving the lights on continually
Procedure/Experimental Design: The MythBusters test common types of lightbulbs: incandescent, fluorescent, metal halide, and even an LED
Results: Even with the fluorescent bulb having the largest start-up surge, needing to be off for 23 seconds before it is more energy efficient to leave it off, it is still a small amount of time before it is more energy efficient to leave them off.
Conclusion: It is better to turn the lights off when leaving the room even for a brief instant.
Busted or Not Busted: Busted
Additional Information:
Mythbusters talked with Mark Reisfelt, manager of the Independent Electric Supply where they purchased their light bulbs. He felt that it was best to turn the lights off. To test the myth, they needed to measure energy usage during startup, maintenance (steady state), and shutdown. For steady state energy consumption, they turned on several different types of bulbs for 60 minutes and measured their consumption using a Kill A Watt:
Incandescent: 90 Watts
Compact Fluorescent: 10 Watts
Halogen: 70 Watts
Metal Halide: 60 Watts
LED: 1 Watts
Fluorescent: 10 Watts
For startup energy consumption, Grant hooked up an inductive current loop to a computer and measured the amount of energy used when the turned on the bulbs. With an inductive current loop, you run a wire through the center, which induces a current in the loop. This current is then measured by a digital sampling oscilloscope. Based on the amount of energy consumed turning on the bulb, they were able calculated how long the bulb would have to be turned off in order to make it worth the energy savings, i.e. "It's best to turn off the bulb if you are leaving the room for":
- Incandescent: 0.36 seconds
- CFL: 0.015 seconds
- Halogen: .51 seconds
- LED: 1.28 seconds
- Fluorescent: 23.3 seconds
In other words, its almost always best to turn the bulb off. Even the 23 seconds for the fluorescent lights isn't very long, and the rest of the times are pretty much blinks of an eye.
Bulb Longevity
They tested one final element of this myth: frequently turning lights on and off decreases their life span, thus leading to greater costs. Grant setup a timer and relay to turn the bulbs on and off repeatedly every 2 minutes. After six weeks, only the LED bulb was still working. Based on this test, they extrapolated that it would take five years of ordinary usage to cause the bulbs to burn out.
Busted or Not Busted: Busted
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